The HIV virus has jumped from primates to people on at least seven separate occasions in recent history, not twice as is commonly thought.
And people in Cameroon are showing up with symptoms of HIV, but are testing negative for both the virus and its primate equivalent SIV, the virus from which HIV is thought to have evolved. That suggests that new strains of an HIV-like virus are circulating in wild animals and infecting people who eat them, sparking fears that such strains could fuel an already disastrous global HIV pandemic.
The warnings come from experts who gathered this week for the annual meeting of the Society for Conservation Biology at Columbia University, New York. They say that deforestation and the trade in bush meat are creating the ideal conditions for new diseases to emerge, as people have ever closer contact with exotic animals that harbour novel pathogens.
The conference reports follow the discovery earlier in 2004 that simian foamy virus, another disease that infects monkeys, has been found in bush-meat hunters and three different species of primates. As yet, it has not caused ill-effects, but it could mutate into something more insidious.
“Basically, this is a virus looking for a disease,” says William Karesh, director of the World Conservation Society’s field veterinary programme.
Despite those concerns, we still do not have a clear idea of how many wild animals are killed and eaten, David Wilkie, co-chair of the Bushmeat Crisis Task Force (BCTF), told the conference. He has carried out the first-ever survey of daily bush-meat consumption by rural communities in Gabon.
Over two years, he documented a flourishing, but previously unrecognised, informal trade in bush meat, where rural communities hunted and ate small game, having already caught most available primates. He thinks official studies of bush meat sold in markets account for only 40 per cent of the total bush meat eaten in the country.
“In the Congo basin alone, between one and five million metric tonnes of bush meat was consumed last year,” says Heather Eves, head of the BCTF, a non-governmental organisation that monitors the trade.
And the dangers of eating such animals are real. The BCTF points out that SIV infection has now been reported in 26 different species of African nonhuman primates, many of which are hunted and sold as food.
The bush-meat trade is not the only way new diseases could jump into humans. The trade in wildlife, both for agriculture and as pets, is a major global business estimated to be worth billions of dollars. In 2002 alone, for instance, over 38,000 mammals, 365,000 birds, two million reptiles, 49 million amphibians, and 216 million fish were imported into the US.
In 2003, monkeypox jumped from pet prairie dogs to their human masters. That “was just a gentle wake-up call,” says Tonie Rocke, an epidemiologist with the US Geological Survey. Previously the disease had only been known to infect humans after bush-meat hunters ate red colobus monkeys.
The trade in exotic farmed meat also appears to have sparked an unusual outbreak of a common human parasite called Trichinella. In 2004, a farmed crocodile in Papua New Guinea was discovered with Trichinella, which was only thought to infect mammals, after being fed wild pig meat (Emerging Infectious Diseases, vol 10, p 1507).
In 1999, another farmed crocodile in Zimbabwe was similarly infected. “There is a strong chance that infected crocodiles may be in other countries, and could infect humans who eat them,” says Edoardo Pozio, a parasitologist at Rome’s institute of public health. People in Papua New Guinea who eat crocodile meat have already been found to have the parasite, which can cause fever, rashes, and respiratory and neurological problems in humans.
Rocke says there are few safeguards to prevent the spread of diseases through the wildlife trade, and is calling for stricter import and quarantine restrictions.
Advantage West Midlands, Jul. 5
A pioneering Worcestershire businessman has developed state-of-the-art x-ray machine software that is poised to play a vital role in the war against smugglers who bring illegal meat and other items into the UK and EU.
With financial assistance from Advantage West Midlands, Mike Lamb’s company Cargo Images Ltd has developed a remote detection system that enables the contents of suitcases to be examined whilst the aircraft is still in flight.
The illegal trade of bushmeat—smoked monkeys, gorilla heads, flying rats and endangered species—is a growing threat to public health in this country since virtually all of the meat is infected and may carry dangerous diseases transferable to humans.
The significant breakthrough made by Cargo Images’ hi-tech process is that it enables every piece of hold luggage and cargo in the aircraft to be examined by HM Customs & Excise officers in the UK, or equivalent in other countries, hours before the aircraft arrives.
If the contents appear to be suspicious, a sophisticated handheld laser scanner zaps and identifies the suspect case at the arrival airport—and it can then be manually inspected with the owner.
The Cargo Images detection system has undergone discrete trials between an overseas airport and the UK where it has proved a great success, with 36,000 bags were inspected.
Mike Lamb, managing director of Cargo Images Ltd, believes that after five years of development, the system is now ready to be installed on major international air routes which are major sources of the bushmeat smuggling trade.
“Our process is great news for British farmers and the Government who may still fear a repeat of the foot & mouth epidemic which cost the country millions and was traced to an illegal meat import,” he said.
“The technology enables the identification of a wide range of items which are of interest to international governments and conservation groups. I really do feel that this system can make a difference and make the world a safer place.”
“I have visited or demonstrated the process to a large number of international governments, such as Australia, New Zealand, the US, Caribbean and the Middle East. The reception has been extremely favourable—this process is affordable, flexible and doesn’t require major staff training or large capital expenditure.
The Cargo Images process will be demonstrated at The Royal Show (Stand 16, Showcase Pavilion) at Stoneleigh this week.
Mike Lamb believes that in addition to UK Government officials visiting Stoneleigh, the international delegations organised by the Foreign & Commonwealth Office will recognise the benefits to their own countries and will install the process themselves.”
Cargo Images was partly assisted in its development research with a £250,000 grant from Advantage West Midlands’ Advantage Technology Fund.
John Marsden, of Innvotec Limited, the company which manages the Advantage Technology Fund, said: “This is a unique and innovative system—and with smugglers coming up with ever more ingenious ways of evading detection, there is a clear need for it.
“One of the fund’s aims is to promote entrepreneurism and Mike Lamb is a classic example of an entrepreneur who has developed a brilliant idea and assembled a strong support team to get the system on to a worldwide stage.”